Systems and methods for transdermal secretion detection

ABSTRACT

Various embodiments of the present invention provide systems and methods for detecting chemicals. As an example, a system is disclosed that includes a chemical sensor, a processor, and a computer readable medium. The computer readable medium includes instructions executable by the processor to: receive a plurality of outputs from the chemical sensor; calculate a baseline value using the plurality of outputs from the chemical sensor; and report an event when the baseline value is exceeded.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 12/716,254 entitled “Systems and Methods for TransdermalSecretion Detection”, and filed Mar. 2, 2010 by Rompa et al.; whichitself claims priority to (i.e., is a non-provisional of) U.S. Pat. App.No. 61/162,638 entitled “Systems and Methods for Detecting TransdermalSecretions of Trace Chemicals While Eliminating Environmental Factors,Normal Human Intervention, and/or Deliberate Attempts to AvoidDetection”, and filed Mar. 23, 2009 by Rompa et al. The entirety of bothof the aforementioned applications is incorporated herein by referencefor all purposes.

BACKGROUND OF THE INVENTION

The present invention is related to chemical detection, and inparticular to systems and methods for detecting transdermal secretions.

Large numbers of individuals are currently housed in prisons. Thisrepresents a significant cost to society both in terms of housingexpense and wasted productivity. To address this concern, house arrestsystems have been developed for use by less violent offenders. Thisallows the less violent offender to be monitored outside of atraditional prison system and allows the offender an opportunity to workand interact to at least some degree in society. The same approach isapplied to paroled prisoners allowing for a monitored transition betweena prison atmosphere and returning to society.

In some cases, it is not practical to parole an offender because theysuffer from an alcohol addiction that may lead to the same activity thatlead to their original incarceration. Present approaches to monitoralcohol consumption costly, time consuming and in some cases,impractical. In other cases, the terms of an individual's parole mayinclude a requirement that the individual abstain from the use ofalcohol, but monitoring adherence to such terms is costly and timeconsuming. In yet other circumstances, it may be possible that anindividual could avoid incarceration altogether if they agree to abstainfrom the use of alcohol. Again, assuring adherence to such terms is atbest costly and time consuming.

Griner Inc. of Newton, Mass. has developed a product that includes atransdermal alcohol monitor with a strap allowing it to be placed aroundthe leg of an individual being monitored. Such an approach offers somehope in portable alcohol monitoring. Unfortunately, the strap has to bemaintained relatively tight to assure reasonable reading. Such is notalways possible due to the movement of the individual being monitored.In some cases, such movement reduced the accuracy of any readings and insome cases results in an inability to rely on the readings. Further,such a device is not easily serviceable and may be susceptible totampering by the monitored individual.

Thus, for at least the aforementioned reasons, there exists a need inthe art for more advanced approaches, devices and systems for detectingalcohol usage by an individual.

BRIEF SUMMARY OF THE INVENTION

The present invention is related to chemical detection, and inparticular to systems and methods for detecting transdermal secretions.

Some embodiments of the present invention provide portable alcoholmonitoring devices. Such devices include a device body, an alcoholsensor, and a liquid cartridge. The alcohol sensor is associated withthe device body, and relies on a liquid supply to perform an alcoholmeasurement on a subject. The liquid cartridge is replaceably coupled tothe device body and provides the liquid supply to the alcohol sensor. Insome instances of the aforementioned embodiments, the liquid cartridgeis filled with water. In one particular instance, the water isdistilled, de-ionized water. The liquid cartridge may be, but is notlimited to, a cylindrical cartridge, or a cubical cartridge.

In some instances of the aforementioned embodiments, the alcoholmonitoring devices further include a securing device that is operable tosecure the device body to the subject. In various instances of theaforementioned embodiments, the alcohol sensor is incorporated in thedevice body, and a force element presses the alcohol sensor toward thesubject. As one example, the force element may be a spring and thealcohol sensor may be coupled to the device body via a bellows. In otherinstances, the device body includes an electronics body and a sensorbody with the sensor body encasing the alcohol sensor and being attachedto the electronics body via a torsion hinge. In such cases, the torsionhinge operates to press the alcohol sensor toward the subject.

In some instances of the aforementioned embodiments, the liquidcartridge is coupled to the body device using tamper resistant hardware.In some cases, the tamper resistant hardware is designed such that it isdamaged upon replacement of the liquid cartridge. As just some examples,the tamper resistant hardware may be, but is not limited to, a tamperresistant cap, and a tamper resistant screw. In particular instances ofthe aforementioned embodiments, the device further includes a proximitydetector that is operable to detect whether the device body is within adesired proximity of the subject. Further, in some instances of theaforementioned embodiments, the device further includes at least onetamper sensor that is operable to detect unauthorized tampering with thedevice.

Other embodiments of the present invention provide portable alcoholmonitoring devices that include a device body, an alcohol sensor that isassociated with the device body, a securing device that is operable tosecure the device body to the subject, and a force element that isoperable to press the alcohol sensor toward the subject.

Yet other embodiments of the present invention provide methods formaintaining alcohol monitoring equipment. Such methods include providinga portable alcohol monitoring device having a device body, an alcoholsensor, and a liquid cartridge. The alcohol sensor is associated withthe device body, and relies on a liquid supply to perform an alcoholmeasurement on a subject. The liquid cartridge is replaceably coupled tothe device body and provides the liquid supply to the alcohol sensor.The methods further include removing a tamper resistant hardwareelement, and in doing so damaging the tamper resistant hardware element.Further, the methods include removing and replacing the liquidcartridge, and replacing the tamper resistant hardware. In some cases,the replacing the liquid cartridge includes refilling an existing liquidcartridge and replacing it, while in other cases replacing the liquidcartridge includes using a different liquid cartridge.

This summary provides only a general outline of some embodimentsaccording to the present invention. Many other objects, features,advantages and other embodiments of the present invention will becomemore fully apparent from the following detailed description, theappended claims and the accompanying drawings and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the various embodiments of the presentinvention may be realized by reference to the figures which aredescribed in remaining portions of the specification. In the figures,similar reference numerals are used throughout several drawings to referto similar components. In some instances, a sub-label consisting of alower case letter is associated with a reference numeral to denote oneof multiple similar components. When reference is made to a referencenumeral without specification to an existing sub-label, it is intendedto refer to all such multiple similar components.

FIGS. 1 a-1 d depict an alcohol monitoring device in accordance withvarious embodiments of the present invention;

FIGS. 2 a-2 c depict another alcohol monitoring device in accordancewith different embodiments of the present invention;

FIGS. 3 a-3 b depict yet another alcohol monitoring device in accordancewith yet other embodiments of the present invention;

FIG. 4 is a flow diagram depicting a process for servicing an alcoholmonitoring device in accordance with some embodiments of the presentinvention;

FIG. 5 depicts the block diagram of a monitoring device capable ofmonitoring subject location as well as alcohol usage;

FIG. 6 is a flow diagram depicting a method in accordance with someembodiments of the present invention for detecting and reportingsecretions;

FIG. 7 is a flow diagram depicting a process for updating detectedoutputs in accordance with various embodiments of the present invention;and

FIG. 8 is a flow diagram showing a method for determining and reportinga secretion in accordance with one or more embodiments of the presentinventions.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is related to chemical detection, and inparticular to systems and methods for detecting transdermal secretions.

Some embodiments of the present invention provide portable alcoholmonitoring devices. Such devices include a device body, an alcoholsensor, and a liquid cartridge. As sued herein, the phrase “device body”is used in its broadest sense to mean a portion of a device includinghardware for performing one or more functions. In some cases, the devicebody may be a case holding one or more functional elements, while inother cases, the device body includes two or more cases with eachholding functional elements. In the aforementioned embodiments, thealcohol sensor is associated with the device body, and relies on aliquid supply to perform an alcohol measurement on a subject. The liquidcartridge is replaceably coupled to the device body and provides theliquid supply to the alcohol sensor. As used herein, the phrase “liquidcartridge” is used in its broadest sense to mean any container capableof holding a liquid.

In some instances of the aforementioned embodiments, the alcoholmonitoring devices further include a securing device that is operable tosecure the device body to the subject. In various instances of theaforementioned embodiments, the alcohol sensor is incorporated in thedevice body, and a force element presses the alcohol sensor toward thesubject. As used herein, the phrase “force element” is used in itsbroadest sense to mean an element capable of providing some level offorce to an object. As one example, the force element may be a springand the alcohol sensor may be coupled to the device body via a bellows.As another example, the force element may be a torsion spring.

In some instances of the aforementioned embodiments, the liquidcartridge is filled with water. In one particular instance, the water isdistilled, de-ionized water. The liquid cartridge may be, but is notlimited to, a cylindrical cartridge, or a cubical cartridge. As usedherein, the phrase “cubicle cartridge” is used in its broadest sense tomean any container having the general shape of a cube where the lengthof the container sides are not necessarily equal. Similarly, the phrase“cylindrical cartridge” is used in its broadest sense to mean anycontainer having he general shape of a cylinder.

In some instances of the aforementioned embodiments, the liquidcartridge is coupled to the body device using tamper resistant hardware.As used herein, the phrase “tamper resistant hardware” is used in itsbroadest sense to mean any hardware element that provides someindication of tampering when it has been tampered with. In some cases,the tamper resistant hardware is designed such that it is damaged uponreplacement of the liquid cartridge. Such damage may be in some cases,irreparable damage. As just some examples, the tamper resistant hardwaremay be, but is not limited to, a tamper resistant cap, and a tamperresistant screw.

Turning to FIG. 1 a, an alcohol monitoring device 100 is depicted inaccordance with various embodiments of the present invention. Alcoholmonitoring device 100 includes a body 105 that includes variousmonitoring and/or tracking circuitry. Such circuitry may include, but isnot limited to, alcohol detection circuitry, location circuitry and/ortamper circuitry. The alcohol detection circuitry may include a fuelcell based on PEM sensor technology available from Giner Inc. of Newton,Mass., or any other alcohol detection sensor known in the art. Themonitoring circuitry may include location monitoring circuitry as isknown in the art, or other monitoring circuitry used to determineattributes and/or location of a monitored individual. In addition, themonitoring circuitry may include transmission and/ore receptioncircuitry as is known in the art for transmitting information fromalcohol monitoring device 100, and receiving information at alcoholmonitoring device 100. The information transmitted by alcohol monitoringdevice may include an indication of whether a monitored individual hasbeen consuming alcohol and to what level the consumption has progressed.The information may be transmitted to a central monitoring station whereit is monitored. Based on the disclosure provided herein, one ofordinary skill in the art will recognize a variety of information thatmay be transmitted to/from alcohol monitoring device, a variety of usesof such information, and a variety of transmission methods and protocolsthat may be utilized in accordance with different embodiments of thepresent invention. The tamper circuitry may include any circuitry knownin the art that are capable of determining whether any interference withalcohol monitoring device 100. Such interference may include, but is notlimited to, blocking the alcohol sensor, interfering with thetransmission of information to/from alcohol monitoring device 100,and/or cutting an attachment securing alcohol monitoring device 100 tothe human subject. Such tamper sensors may include, but are not limitedto, a proximity sensor that is able to determine whether alcoholmonitoring device 100 is within reasonable proximity of the skin of themonitored individual. Based on the disclosure provided herein, one ofordinary skill in the art will recognize a variety of tamper sensorsthat may be used in conjunction with the various embodiments of thepresent invention. The various sensors included in alcohol measurementdevice 100 may include, but are not limited to, blockage sensorindicating that no gas is being allowed to reach an included alcoholsensor, a temperature sensor, a proximity sensor indicating that alcoholmeasurement device is within a defined range of the monitoredindividual, a skin probe capable of measuring skin resistance as anindication of whether alcohol measurement device is still being worn bythe monitored individual, and/or the like. Based on the disclosureprovided herein, one of ordinary skill in the art will recognize avariety of other sensors that may be used in relation to differentembodiments of the present invention.

Body 105 is attachable to a human subject using a strap 130. Strap 130is attachable using some sort of buckle or other connector as are knownin the art. In some cases, strap 130 includes a continuity detector (notshown) imbedded therein. In one particular embodiment of the presentinvention, the continuity detector is an electrical conductor extendingaround strap 130 and making a connection in body 105. As such, whenstrap 130 is either unbuckled or cut, the electrical conductor is brokenand the break is detected by circuitry within body 105. In otherparticular embodiments of the present invention, the continuity detectoris a fiber optic conductor that may similarly be used to determinewhether strap 130 has been unbuckled or cut. Based on the disclosureprovided herein, one of ordinary skill in the art will appreciate avariety of straps and associated securing devices that may be used inaccordance with different embodiments of the present invention to securebody 105 to a monitored individual. In one particular embodiment, strap130 includes an outer case with an imbedded fiber optic continuityconductor and banding for added strength.

Body 105 includes an alcohol sensor 110 that is maintained at acontrolled distance from the monitored individual's skin by a dermalseal 125 and a telescoping housing 120. The combination of dermal seal125 and telescoping housing 120 create a reasonably stable gas region127 between alcohol sensor 110 and the monitored individual's skin.Dermal seal 125 may be, for example, a set of foam pads that are capableof creating a reasonable seal with the skin of a monitored individual,and yet are comfortable to the monitored individual. In particularinstances, the foam pads are made of closed cell foam that allows forpositioning and ergonomic fit. Based on the disclosure provided herein,one of ordinary skill in the art will recognize other materials that maybe used to form dermal seal 125 in accordance with the variousembodiments of the present invention. Telescoping housing 120 isoperable to press alcohol sensor 110 near the skin of the monitoredindividual. Because of this, alcohol sensor 110 is maintained at areasonably constant distance from the monitored individual's skin evenwhen the individual is moving. This promotes better readings fromalcohol sensor 110 without the need to tighten strap 130 beyond acomfortable point. As more fully described below, in one embodiment ofthe present invention, telescoping housing 120 includes an expandablebellows 122 that allows for movement of alcohol sensor 110 relative tobody 105, and a spring (not shown) that presses alcohol sensor 110 anddermal seal 125 away from body 105 and toward the human subject's skin.In particular instances of the aforementioned embodiments, expandablebellows 122 is made of rubber, while in other instances it is formed ofsome type of flexible plastic. Based on the disclosure provided herein,one of ordinary skill in the art will recognize a variety of materialsthat may be used to create expandable bellows 122 in accordance withvarious embodiments of the present invention.

Body 105 also includes a water tight compartment 140 that includes areplaceable liquid cartridge (not shown) and electronics (not shown) foroperating alcohol monitoring device 100. Water tight compartment 140 isaccessible by removing temper resistant screws 142. In some embodimentsof the present invention, tamper resistant screws 142 may require aspecial tool for removal to minimize the possibility that a monitoredindividual will open water tight compartment 140 and attempt tointerfere or otherwise control the operation of alcohol monitoringdevice 100. In other embodiments of the present invention, tamperresistant screws 142 are only one way devices allowing for the closureof water tight compartment 140. Opening water tight compartment 140requires the destruction of tamper resistant screws 142. When watertight compartment 140 is to be resealed, a new pair of tamper resistantscrews is required.

In this way, any unauthorized opening of water tight compartment 140will be readily apparent. In some cases, the aforementioned approach maybe combined with a sensor (not shown) that indicates that water tightcompartment 140 is open. Thus, when water tight compartment 140 isopened an error message may be prepared and transmitted to a centralmonitoring location by alcohol monitoring device 100. This would allowfor detection of any tampering within a reasonable period of when thetampering occurred, and additional scrutiny of the monitored individualsbehavior during that period.

Turning to FIG. 1 b, a cut away view of alcohol monitoring device 100 ispresented. Of interest, expandable bellows 122 are shown as having aserpentine shape that allows for extension away from and toward body105. Also shown is a spring 150 that provides the force for movingalcohol sensor 110 toward the skin of the monitored individual. Inaddition, a fiber optic conductor 132 is shown extending through strap130. The interior of water tight compartment 140 is shown with an area144 to hold a replaceable liquid cartridge (not shown), and an area 146for electronic circuitry (not shown) for controlling the variousoperations of alcohol monitoring device 100. A bulk head 148 provides anarea for spring 150 to press against and forms the outer wall of watertight compartment 140.

Turning to FIG. 1 c, an exploded view of alcohol monitoring device 100is presented. As shown, a battery 180 is connected to body 105 using aremovable connector plate 182. Battery 180 provides power to operatealcohol monitoring device 100. A replaceable liquid cartridge 160 isplaced in water tight compartment 140 and held in place by an outerplate 162 that is held in place by tamper resistant screws 142. In oneembodiment of the present invention, liquid cartridge 160 is a plasticcontainer that includes a supply of water used to operate alcohol sensor110. Use of such a liquid cartridge allows for easy replenishment ofwater. In some cases, the water is distilled water that is not alwaysreadily available in the field. By using such a replaceable liquidcartridge, quick and easy replenishment of any desired liquid isrendered more manageable. A feed line 164 allows for dispersing liquidfrom liquid cartridge 160 to alcohol sensor 110. In some cases, feedline 164 is implemented as a wick capable of transporting a definedsaturation of liquid.

An electronic circuit board 170 holds electronics responsible forcontrolling the various operations of alcohol monitoring device 100, andis connected in water tight compartment 140. A case cover 194 and bulkhead 148 separates water tight compartment 140 from alcohol sensor 110.Spring 150 presses alcohol sensor 110 away from body 105 and toward theskin of the monitored individual. A sensor carriage 196 captures alcoholsensor 110 and allows it to move in and out and stay within a desiredrange of the monitor individual's skin. Expandable bellows 122 contactdermal seal 125 that includes foam pads 198 on opposite sides.

Turning to FIG. 1 d, an alternative embodiment of a body 101 that may beused in place of body 105 is depicted. As shown, body 101 includes anopening in which a spring 151 is placed. Spring 151 is used similar tospring 150 to press an alcohol sensor (not shown) away from body 101 andtoward the skin of the monitored individual. A cylindrical liquidcartridge 161 may be placed inside of spring 151. One end of cylindricalcartridge 161 includes a wick that assures a defined range of moisturesaturation in proximity of the alcohol sensor. Cylindrical cartridge 161is designed to be replaceable in the field. In one embodiment of thepresent invention, cylindrical cartridge 161 is a plastic container thatincludes a supply of water used to operate alcohol sensor 110. Use ofsuch a replaceable cartridge allows for easy replenishment of water. Insome cases, the water is distilled water that is not always readilyavailable in the field. By using such a replaceable liquid cartridge,quick and easy replenishment of any desired liquid is rendered moremanageable.

Spring 150 and cylindrical cartridge 161 are held in place by tamperresistant cap 185. Tamper resistant cap 185 is installed by placing itonto body 101 over spring 150 and cylindrical cartridge 161 and turned aquarter turn. When initially pressed onto body 101, tamper resistant cap185 causes a flat spring 187 to press inward. Upon turning tamperresistant cap 185, it locks into body 101 with flat spring 187 extendingaway from body 101 into a void on tamper resistant cap 185. In theextended condition, flat spring 187 precludes twisting tamper resistantcap 185 to open body 101. Thus, the only way to access cylindricalcartridge 161 is to break tamper resistant cap 185. Thus, anyunauthorized access to body 101 will be readily apparent. When replacingcylindrical cartridge 161 with a full cartridge, tamper resistant cap185 is broken and a new cylindrical cartridge 161 is inserted in placeof the replaced cartridge. A new tamper resistant cap 185 is theninstalled.

Turning to FIG. 2 a, an alcohol monitoring device 200 is depicted inaccordance with various embodiments of the present invention. Alcoholmonitoring device 200 includes a body 205 that includes variousmonitoring and/or tracking circuitry. Such circuitry may include, but isnot limited to, alcohol detection circuitry, location circuitry and/ortamper circuitry. The alcohol detection circuitry may include a fuelcell based on PEM sensor technology available from Giner Inc. of Newton,Mass., or any other alcohol detection sensor known in the art. Themonitoring circuitry may include location monitoring circuitry as isknown in the art, or other monitoring circuitry used to determineattributes and/or location of a monitored individual. In addition, themonitoring circuitry may include transmission and/ore receptioncircuitry as is known in the art for transmitting information fromalcohol monitoring device 200, and receiving information at alcoholmonitoring device 200. The tamper circuitry may include any circuitryknown in the art that are capable of determining whether anyinterference with alcohol monitoring device 200.

Body 205 is attachable to a human subject using a strap 230. Strap 230is attachable using some sort of buckle or other connector as are knownin the art. In some cases, strap 230 includes a continuity detector(e.g., either an electrical conductor or optical conductor) imbeddedtherein. As such, when strap 230 is either unbuckled or cut, theconductor is broken and the break is detected by circuitry within body205. In one particular embodiment, strap 230 includes an outer case withan imbedded fiber optic continuity conductor and banding for addedstrength.

Body 205 includes an alcohol sensor body 222 and an electronics body224. Electronics body 224 houses a battery and electronic circuitryresponsible for the various operations of alcohol monitoring device 200.Alcohol sensor body 222 holds a sensor housing 225 that articulates tostay in contact with the skin of a monitored individual. In some cases,alcohol sensor body 222 may include a spring and an expandable bellowssimilar to that discussed above in relation to alcohol monitoring device100. Alcohol sensor body 222 operates to hold an alcohol sensor 210within a defined range of the skin of a monitored individual. Thisassures that more accurate readings are possible.

Alcohol sensor body 222 is held in relation to electronics body 224 by asupport bracket 235 connected via torsion hinges 236 on either side.Torsion hinges 236 operate to force alcohol sensor body 222 toward thecenter of strap 230, thus causing alcohol sensor 210 to be disposednearer the skin of the monitored individual. In one particularembodiment of the present invention, torsion hinges 236 are springloaded hinges providing only a minimal amount of pressure sufficient tokeep sensor body 222 in contact the appropriate skin.

Turning to FIG. 2 b, an exploded view of alcohol monitoring device 200is provided. In particular, support bracket 235 including torsion hinges236 is shown disconnected from both alcohol sensor body 222 andelectronics body 224. In addition, a tamper resistant cap 272 is removedfrom electronics body 224 revealing a battery 270. Tamper resistant cap272 is installed by placing it onto electronics body 224 over battery270 and turned a quarter turn. Tamper resistant cap 272 may be installedover a flat spring similar to that discussed above in relation to tamperresistant cap 185. Such an approach requires damaging tamper resistantcap 272 whenever it is removed rendering any tampering evident.Alternatively, or in addition, tamper resistant cap 272 may require aspecialized tool for removal to minimize the possibility that amonitored individual will tamper with alcohol monitoring device 200.Further, in some cases, the aforementioned approaches may be combinedwith a sensor (not shown) that indicates that tamper resistant cap 272has been removed. Thus, when tamper resistant cap 272 is removed, anerror message may be prepared and transmitted to a central monitoringlocation by alcohol monitoring device 200. This would allow fordetection of any tampering within a reasonable period of when thetampering occurred, and additional scrutiny of the monitored individualsbehavior during that period.

Turning to FIG. 2 c, an exploded view of alcohol sensor body 222 isshown. In this embodiment, alcohol sensor body 222 includes an outercasing 226 into which alcohol sensor 210 is placed and secured thereinusing a face plate 225 that doubles as a dermal seal. In some cases,dermal seal 225 is made of a plastic material sturdy enough to maintainalcohol sensor 210 in place and pliable enough when placed in relationto human skin to render a reasonable seal. Based on the disclosureprovided herein, one of ordinary skill in the art will recognize avariety of materials that may be used to create dermal seal 225 inaccordance with different embodiments of the present invention.

Outer casing 226 additionally houses a replaceable liquid cartridge 228that is maintained in place by a tamper resistant cap 285. A wick orliquid feed mechanism traverses an inner wall 228 of outer casing toallow liquid from liquid cartridge 228 to reach alcohol sensor 210. Inone embodiment of the present invention, replaceable liquid cartridge228 is a plastic container that includes a supply of water used tooperate alcohol sensor 210. Use of such a liquid cartridge allows foreasy replenishment of water. In some cases, the water is distilled waterthat is not always readily available in the field. By using such areplaceable liquid cartridge, quick and easy replenishment of anydesired liquid is rendered more manageable.

Tamper resistant cap 285 is installed by placing it onto outer casing226 over liquid cartridge 228 and turned a quarter turn. Tamperresistant cap 285 may be installed over a flat spring similar to thatdiscussed above in relation to tamper resistant cap 185. Such anapproach requires damaging tamper resistant cap 285 whenever it isremoved rendering any tampering evident. Alternatively, or in addition,tamper resistant cap 285 may require a specialized tool for removal tominimize the possibility that a monitored individual will tamper withalcohol monitoring device 200. Further, in some cases, theaforementioned approaches may be combined with a sensor (not shown) thatindicates that tamper resistant cap 285 has been removed. Thus, whentamper resistant cap 285 is removed, an error message may be preparedand transmitted to a central monitoring location by alcohol monitoringdevice 200. This would allow for detection of any tampering within areasonable period of when the tampering occurred, and additionalscrutiny of the monitored individuals behavior during that period.

Turning to FIGS. 3 a-3 b, two views of another alcohol monitoring device300 is depicted in accordance with yet other embodiments of the presentinvention. As shown, alcohol monitoring device 300 includes an alcoholsensor 310 that is maintained a desired distance from the skin of amonitored individual by a dermal seal 325. Alcohol sensor 310 ismaintained in proximity to the skin though use of a flexible sub-strap335 that is more flexible than a main strap 330. Flexible sub-strap 335is attached to a sensor assembly including alcohol sensor 310 and dermalseal 325. This allows alcohol sensor 310 to be maintained near the skinof the monitored individual without requiring that the entire alcoholmonitoring device 300 be maintained in the same proximity. This allowsfor greater comfort and improved alcohol measurement results.

Turning to FIG. 4, a flow diagram 400 depicts a process for servicing analcohol monitoring device in accordance with some embodiments of thepresent invention. Following flow diagram 400, a full liquid cartridgeis initially installed in an alcohol measuring device (block 405). Thisprocess may include, for example, inserting a new liquid cartridge intoan opening of the alcohol monitoring device designed to hold thecartridge. Such a liquid cartridge may include, for example, a supply ofdistilled, de-ionized water that is designed to support operation of thealcohol monitoring device for a desired range of time. Inclusion of alarger cartridge allows for greater extension of device operationbetween maintenance intervals.

Once the liquid cartridge is installed (block 405), tamper resistanthardware is installed over the liquid cartridge to hold it in place(block 410). This may include, but is not limited to, installing a plateusing tamper resistant screws or covering the opening through which theliquid cartridge is inserted using a tamper resistant cap. Further, itmay include turning on a sensor that indicates that a tamper hasoccurred if such circuitry is available. The alcohol monitoring devicemay then be deployed (block 415). This may include securing the alcoholmeasuring device to a monitored individual.

During deployment, it may be determined whether the liquid in theinstalled liquid cartridge is low (block 420). This may include, forexample, determining that the installed liquid sensor has been in for acertain time period and that it needs to be replaced. In other cases,the alcohol monitoring device may be able to detect when the liquid inthe liquid cartridge is low. In such a case, a sensor message may betransmitted to a central monitoring system. In either case, where it isdetermined that the liquid level is potentially or actually low, thealcohol monitoring device is serviced. Such service may includesummoning the monitored individual to a prescribed location where thedevice is serviced. This may be a scheduled service time corresponding,for example, to a visit with a parole officer. Alternatively, atechnician or parole officer may visit the monitored individual andservice the alcohol monitoring device in situ. Use of a cartridge basedapproach to the liquid reservoir makes such servicing possible.

The servicing includes removing the tamper resistant hardware holdingthe liquid cartridge in place (block 425). This may include destroyingpart of the hardware which will need to be replaced with new parts. Anew liquid cartridge is then inserted in place of the removed liquidcartridge rendered accessible by removing the tamper resistant hardware(block 430), and replacement tamper resistant hardware is installed tohold the replacement liquid cartridge in place (block 435).

Turning to FIG. 5, a tracking and alcohol monitoring system 500 isdepicted in accordance with some embodiments of the present invention.Tracking and monitoring system 500 includes a multi-purpose monitoringdevice 520 that is capable of both tracking an individual and monitoringalcohol consumption of the individual. This device can be incorporatedin the electronics of the devices of FIGS. 1, 2 and 3. As shown,multi-purpose monitoring device 520 includes a GPS receiver 522 that iscapable of receiving GPS information from GPS satellites 345, 346, and347 respectively. GPS receiver 322 is useful for determining physicallocations, i.e. whenever GPS receiver 322 is powered-on, and also aslong as receiving sufficient GPS satellites signal transmissions.

Multi-purpose monitoring device 520 includes a device ID 521 that may bemaintained in a memory 525, and thus is accessible by a controller 527.Controller 57 is able to interact with GPS receiver 522 and memory 525at times for storing and generating records of successively determinedGPS locations. Controller 527 may be, but is not limited to, amicroprocessor, microcontroller or other device known in the art that iscapable of executing software or firmware instructions. Memory 525 maybe any type of memory known in the art such as, for example, a EEPROM orRAM memory. Instructions executable by controller 527 may be maintainedin memory 525.

Controller 527 of subject device 520 at times functions in conjunctionwith a cellular transceiver 528 to send and receive data and signalsthrough cellular communication system 590. This link at times is usefulfor passing information and/or control signals between a centralmonitoring system (not shown) and multi-purpose monitoring device 520.The information transmitted may include, but is not limited to, locationinformation, alcohol information, and information about the status ofmulti-purpose monitoring device 520. Based on the disclosure providedherein, one of ordinary skill in the art will recognize a variety ofinformation that may be transferred via cellular communication system590.

Various embodiments of multi-purpose monitoring device 520 include avariety of sensors capable of determining the status of multi-purposemonitoring device 520, and of the individual associated therewith. Forexample, a status monitor 526 may include one or more of the followingsubcomponents: a set of shielding sensors 529 that are capable ofdetermining whether subject device is being shielded from receiving GPSsignals and/or if GPS jamming is ongoing, a set of device healthindicators 530, a tamper sensor 531 capable of determining whetherunauthorized access to subject device 520 has occurred or whethersubject device 520 has been removed from an associated human subject, amotion/proximity sensor 532 capable of determining whether subjectdevice 520 is moving and/or whether it is within proximity of anindividual associated with multi-purpose monitoring device 520, and/oran alcohol sensor 533 such as that described herein. Based on thedisclosure provided herein, one of ordinary skill in the art willrecognize a variety of shielding sensors, a variety of device healthtransducers and indicators, a variety of tamper sensors, variousdifferent types of motion sensors, different proximity to human sensors,and various human body physical measurement sensors or transducers thatmay be incorporated into subject device 520 according to variousdifferent instances and/or embodiments of the present invention. In somecases, transmission of alcohol data is done at one frequency, and housearrest information is transmitted at another frequency. In oneparticular embodiment of the present invention, house arrest information(i.e., location information) is transmitted using a 300 MHz-320 MHz, andalcohol information is transmitted using a 902 MHz-928 MHZ band. Thehigher frequency band allows for transmission of substantial amounts ofinformation, while the lower frequency band allows for transmission ofsmaller amounts of data.

Turning to FIG. 6, a flow diagram 600 depicts a method in accordancewith some embodiments of the present invention for detecting andreporting secretions. In some cases, the process of flow diagram 600 isimplemented as computer executable instructions. Such computerexecutable instructions may be maintained in a memory that iscommunicably coupled to a processor. The processor may access andexecute the instructions. Following flow diagram 600, a monitoringdevice is prepared (block 605). Such preparation may include, but is notlimited to, configuring any configurable elements of the monitoringdevice, assuring proper operation of the monitoring device, and//or thelike. Where, for example, the monitoring device may be alcoholmonitoring device 100 described above, or another monitoring devicecapable of detecting one or more chemicals secreted transdermally. Inaddition, the monitoring device is attached to a monitored subject(block 610). This may include, for example, strapping a monitoringdevice around the leg of a human subject in such a way that it isdifficult to remove, and if removed it provides some indication thattampering has occurred. Based upon the disclosure provided herein, oneof ordinary skill in the art will recognize a variety of approaches andequipment that may be used to attach the monitoring device to amonitored subject.

A sensor associated with the monitoring device senses transdermalchemical secretions from the monitored subject and provides anindication of the transdermal chemical secretions as a detected outputto a processor of the monitoring device (block 615). One example of aprocess for updating detected outputs from the sensor is shown as flowdiagram 700 of FIG. 7. Following flow diagram 700, it is determinedwhether a detector timer has expired (block 705). In one particularembodiment of the present invention, the detector timer expires andresets each five minutes. Based upon the disclosure provided herein, oneof ordinary skill in the art will recognize other frequencies at whichthe detected output may be received from the sensor. Once the timerexpires (block 705), the detected output is stored to a FIFO (FirstIn—First Out) memory (block 710). The memory holds enough samples (i.e.,instances of detected output sampled at periods over time) to run anydetection algorithm and filtering employed. In one particular embodimentof the present invention, the memory holds twelve samples.

Returning to flow diagram 600, it is determined whether a baseline hasbeen established (block 620). Where a baseline has not been established(block 620), a baseline algorithm is performed (block 690). The baselinealgorithm establishes a baseline value for comparison with laterdetected outputs to determine whether a positive detection of a chemicalsecretion is identified. In some embodiments of the present invention, acalculated transdermal chemical concentration (TCC) is a linear valuecalculated using the following slope intercept equation:y=mx+b,where m represents slope and b is the y-intercept. In this case, thevalue of the slope is calculated in accordance with the followingequation:

$m = {\frac{{TCC}_{\max} - {TCC}_{\min}}{{Count}_{\max} - {Count}_{\min}}.}$Effectively, the baseline algorithm modifies the value of Count_(min)for exam individual such that the slope and intercept is changed foreach individual.

In particular, the baseline algorithm the standard deviation iscalculated in accordance with the following equations:

${S = \sqrt{\frac{\sum( {x - \overset{\_}{X}} )^{2}}{n - 1}}},{and}$${S_{\overset{\_}{X}} = \frac{S}{\sqrt{n}}},{and}$ v = (n − 1)where n is the number of samples utilized and v=the degrees of freedom.The value of S _(x) is used with the Student's t-distribution for theappropriate degrees of freedom to set a statistical probability boundaround the arithmetic mean value X. Depending upon the desiredprobability and the number of samples used to perform the baseline, anappropriate Critical Value (CV) of t is employed from standardstatistical tables of the ordinates of the t distribution for degrees offreedom v. Where, for example, a 95% confidence level (probabilityα=1.0−0.95=0.05 in the two-tailed t distribution) is desired, the value2.571 is selected when the number of samples used is six and v=5. Asanother example, where a probability of 99.5% is desired, the value4.773 is employed with the same sample size and degrees of freedom. Anupper limit and lower limit are set in accordance with the followingequations:lower limit= x −CV*S _(x) ; andupper limit= x +CV*S _(x) .Thus, using the example of 95% confidence and six samples, theappropriate critical value is 2.571 yielding the following equations forthe upper limit and the lower limit:lower limit= x−(2.571*S _(x) ) andupper limit= x+(2.571*S _(x) ).

From this, a 95% statistical confidence interval or “difference limit” Δlimit is calculated as the simple difference between the upper limit andlower confidence limits. If Δ limit is less than a determined value(i.e., a limit set point), then it is determined that there is at leastthe corresponding probability that the true mean of the n samples hasbeen found. Thus, for example, where the value 2.571 is used with thenumber of degrees of freedom being five a 95% probability is achievedwhere the difference (i.e., Δ limit) is less than the determined value.In this case, a baseline has been achieved and the baseline value is setto be the calculated arithmetic mean of the n samples.

Alternatively, where a baseline has been established (block 620), it isdetermined whether a spike filter is turned on (block 625). Where thespike filter is turned on (block 625), spike filtering is performed(block 630). The spike filter is used to eliminate spurious readingsthat may be identified by how far from an expected value they fall. Inone particular embodiment of the present invention, the spike filteridentifies a received detected output (i.e., TCC_(t)) as a spike whereone or both of the following conditions is met: the immediatelypreceding detected output (i.e., TCC_(t-1)) is less greater than adefined value, and the received detected output (i.e., TCC_(t)) minusthe immediately preceding detected output (i.e., TCC_(t-1)) is greaterless than the defined value. Where the defined value is 0.02, thefollowing pseudo-code describes the operation of the spike filter:

IF (TCC_(t−1) < 0.02 AND (TCC_(t) − TCC_(t−1)) > 0.02) { Spike FilterSatisfied } ELSE { Spike Filter Not Satisfied }Where the spike filter is not satisfied (block 635), the detected output(current TCC) is rejected (block 695) and the process returns to awaitreception of the next detected output (block 615). Alternatively, whereeither the spike filter is not turned on (block 625) or the spike filteris satisfied (block 635), it is determined whether a duration filter isturned on (block 640).

Where the duration filter is turned on (block 640), duration filteringis applied (block 645). The duration filter is used to assure thatwhatever positive chemical detection that has occurred continues for aperiod of time before it is identified as reliable and reported. Where,for example, the chemical being detected is alcohol, physiology assuresthat the period of active detection extends for a substantial period oftime suggesting that a positive detection that lasts for only a shortperiod may be a false positive and should not be reported. In oneparticular embodiment of the present invention, the duration filter issatisfied where the six preceding detected outputs (i.e., TCC_(t-5),TCC_(t-4), TCC_(t-3), TCC_(t-2), TCC_(t-1), TCC_(t)) are all greaterthan a defined value. Where the defined value is 0.02, the followingpseudo-code describes the operation of the duration filter:

IF (TCC_(t−5)>0.02 AND TCC_(t−4)>0.02 AND TCC_(t−3)>0.02 ANDTCC_(t−2)>0.02 AND TCC_(t−1)>0.02 AND TCC_(t)>0.02) { Duration FilterSatisfied } ELSE { Duration Filter Not Satisfied }Where the duration filter is not satisfied (block 650), the processreturns to await reception of the next detected output (block 615)without reporting an event. Alternatively, where either the durationfilter is not turned on (block 640) or the duration filter is satisfied(block 650), it is determined whether a slope filter is turned on (block655).

Where the duration filter is turned on (block 640), duration filteringis applied (block 645). The duration filter is used to assure thatwhatever positive chemical detection that has occurred continues for aperiod of time before it is identified as reliable and reported. Where,for example, the chemical being detected is alcohol, physiology assuresthat the period of active detection extends for a substantial period oftime suggesting that a positive detection that lasts for only a shortperiod may be a false positive and should not be reported. In oneparticular embodiment of the present invention, the duration filter issatisfied where the six preceding detected outputs (i.e., TCC_(t-5),TCC_(t-4), TCC_(t-3), TCC_(t-2), TCC_(t-1), TCC_(t)) are all greaterthan a defined value. Where the defined value is 0.02, the followingpseudo-code describes the operation of the duration filter:

IF (TCC_(t−5)>0.02 AND TCC_(t−4)>0.02 AND TCC_(t−3)>0.02 ANDTCC_(t−2)>0.02 AND TCC_(t−1)>0.02 AND TCC_(t)>0.02) { Duration FilterSatisfied } ELSE { Duration Filter Not Satisfied }Where the duration filter is not satisfied (block 650), the processreturns to await reception of the next detected output (block 615)without reporting an event. Alternatively, where either the durationfilter is not turned on (block 640) or the duration filter is satisfied(block 650), it is determined whether a slope filter is turned on (block655).

Where the slope filter is turned on (block 655), slope filtering isapplied (block 660).

The slope filter is used to assure that reporting of a chemicaldetection is only done where the quantity of the detected chemical isincreasing. Where, for example, the chemical being detected is alcohol,physiology assures that the period of active detection includes an upslope extending over a first period of substantial duration, and a downslope extending over a second period of substantial duration. Assuringboth duration and an up slope avoids reporting of less significantevents in favor of reporting only more significant events. In oneparticular embodiment of the present invention, the slope filter issatisfied where the preceding detected output (i.e., TCC_(t-1)) is lessthan the current detected output (TCC_(t)). The following pseudo-codedescribes the operation of the slope filter:

IF (TCC_(t−1)<TCC_(t)) { Slope Filter Satisfied } ELSE { Slope FilterNot Satisfied }Where the slope filter is not satisfied (block 665), the process returnsto await reception of the next detected output (block 615) withoutreporting an event. Alternatively, where either the slope filter is notturned on (block 655) or the slope filter is satisfied (block 665), adetection algorithm is performed, the occurrence of an event isdetermined, and any event is reported (block 670). An example ofperforming a detection algorithm, determination of an event, andreporting is discussed below in relation to a flow diagram 800 of FIG.8.

Turning to FIG. 8, flow diagram 800 shows a method for determining andreporting a chemical event in accordance with one or more embodiments ofthe present inventions. Following flow diagram 800, the most recentdetected output (i.e., TCC_(t)) is accessed from the memory where thedetected outputs are stored (block 805), and the detected output offsetby x (i.e., TCC_(t-x)) is accessed (block 810).). In some cases, thealgorithm is a differenced moving average where the difference (i.e., x)equals six samples taken across successive equal time periods “t”. Thedetected output offset by x (i.e., TCC_(t-x)) is subtracted from themost recent detected output (i.e., TCC_(t)) to yield a Delta Value inaccordance with the following equation (block 815):Delta Value=TCC_(t)−TCC_(t-x).The calculated Delta Values are then arithmetically averaged to form amoving average of sample size x to yield a Moving Average Delta (block820). As an example, the moving average works on a fixed sample sizethat is moved across a larger set of samples.

At the conclusion of the first two x-period moving averages, astatistical comparison of the first x period moving average and thesecond x period moving average is performed (block 830). In some cases,the first x samples and the second x samples overlap by one point toensure that single extreme values at the cusp of the two time seriesaffect their independent statistical variances S² equally. Thisstatistical comparison statistically evaluates the difference betweenthe most recent x period moving average and the immediately preceding xperiod moving average. To do this, standard statistical tests may beemployed such as, for example, a Student's ‘t’. In one particular case,the statistical tests are used to evaluate the null hypothesis (H₀) thatthe means are equivalent at a defined probability (α). In one case, thedefined probability is 99% (i.e., α=0.01). In such a case, thestatistical comparison of the proximate moving averages (block 820)determines whether a difference between the moving averages (i.e., thedifference between Average Delta_(t) and Average Delta_(t-1)) has lessthan or equal to a 1% probability of being random or due solely tochance.

It is then determined whether the most recent moving average AverageDelta_(t) is positive (block 835), and whether the difference betweenthe moving averages is significant (block 840). Where either thedifference is insignificant (block 840) or the most recent movingaverage is not positive (block 835), the process ends (block 850)without reporting an event. Otherwise, where both the difference issignificant (block 840) and the most recent moving average is positive(block 835), a detection event is reported (block 845). This includesreporting the x most recent detected outputs. Thus, for example, where xis six, the values corresponding to TCC_(t-5), TCC_(t-4), TCC_(t-3),TCC_(t-2), TCC_(t-1), and TCC_(t) are all reported. Such reporting mayinclude, but is not limited to, transferring the detection event datafrom the monitoring device to a central monitoring system. This mayinclude, but is not limited to, transferring the data across a wirelesstelephone network, across a wired telephone network, across theInternet, across other networks known in the art, and/or combinationsthereof.

In conclusion, the present invention provides for novel systems,devices, and methods for monitoring alcohol consumption by humansubjects. While detailed descriptions of one or more embodiments of theinvention have been given above, various alternatives, modifications,and equivalents will be apparent to those skilled in the art withoutvarying from the spirit of the invention. Therefore, the abovedescription should not be taken as limiting the scope of the invention,which is defined by the appended claims.

What is claimed is:
 1. A method for detecting chemical secretions, themethod comprising: receiving at least a first value and a second valuefrom a chemical sensor attached to a monitored individual; calculating abaseline value using at least the first value and the second value; andreporting an event when the baseline value is exceeded.
 2. The method ofclaim 1, wherein reporting the event when the baseline value is exceededincludes: calculating a difference between the first value and thesecond to yield a delta value; averaging the delta value with previouslycalculated delta values to yield an average delta value; comparing theaverage delta value with a previously calculated average delta value toyield a significance factor; and reporting the event only when thesignificance factor exceeds the baseline value.
 3. The method of claim1, wherein calculating the baseline value includes: calculating a meanvalue of the plurality of outputs to a confidence of greater than ninetypercent.
 4. The method of claim 1, wherein the method further comprisesfiltering the plurality of outputs using one or more filters selectedfrom a group consisting of: a slope filter, a duration filter, and aspike filter.
 5. A system, the system comprising: a monitoring deviceattachable to a monitored individual, wherein the monitoring deviceincludes a chemical sensor, a processor, and a non-transitory computerreadable medium; and wherein the chemical sensor is operable torepeatedly sense a characteristic of the monitored individual to yield afirst value corresponding to the characteristic at a first time and asecond value corresponding to the characteristic at a second time;wherein the non-transitory computer readable medium includesinstructions executable by the processor to: compare the second value ofthe chemical sensor with a baseline value, wherein the baseline value isgenerated based at least in part on the first value; and report an eventwhen the baseline value is exceeded.
 6. The system of claim 5, whereinthe characteristic is a level of alcohol consumed by the monitoredindividual.
 7. The system of claim 5, wherein reporting the eventincludes reporting a subset of the plurality of the outputs from thechemical sensor.
 8. The system of claim 5, wherein reporting the eventdoes not occur until a baseline value is available.
 9. The system ofclaim 5, wherein the generating the baseline value includes calculatingthe baseline value based at least in part on the first value.
 10. Thesystem of claim 9, wherein calculating the baseline value based at leastin part on the first value derived from sensing the characteristic ofthe monitored individual results in a baseline value tailored to themonitored individual.
 11. The system of claim 5, wherein generating thebaseline value based at least in part on the first value derived fromsensing the characteristic of the monitored individual results in abaseline value tailored to the monitored individual.
 12. The system ofclaim 5, wherein the chemical sensor is operable to be attached to oneof a first individual and a second individual, and wherein the samealgorithm used to generate the baseline value for a first individual isused to calculate the baseline value for a second individual.
 13. Thesystem of claim 5, wherein the baseline value is generated based upon analgorithm dependent upon at least one variable received as an input, andwherein the algorithm is independent of one or more variables selectedfrom a group consisting of: the gender of the individual, the weight ofthe individual, the height of the individual, and food intake of theindividual.
 14. The system of claim 5, wherein the computer readablemedium includes instructions executable by the processor to: perform aslope filter function.
 15. The system of claim 5, wherein the computerreadable medium includes instructions executable by the processor to:perform a spike filter function.
 16. The system of claim 5, wherein thecomputer readable medium includes instructions executable by theprocessor to: perform a duration filter function.
 17. The system ofclaim 5, wherein the chemical sensor furtherer yields a third valuecorresponding to the characteristic at a third time, wherein thecomputer readable medium further includes instructions executable by theprocessor to: calculate a difference between the first value and thethird value to yield a delta value; average the delta value withpreviously calculated delta values to yield an average delta value; andcompare the average delta value with a previously calculated averagedelta value to yield a significance factor.
 18. The system of claim 17,wherein the event is reported only when the significance factor exceedsthe baseline value.
 19. The system of claim 5, wherein the baselinevalue is generated based upon an algorithm, and wherein the algorithmincludes: calculating a mean value of the plurality of outputs to withina defined confidence.
 20. The system of claim 19, wherein the definedconfidence is greater than ninety percent probability.
 21. The system ofclaim 5, wherein the chemical sensor is a transdermal alcohol sensor.22. A system, the system comprising: a monitoring device attachable to amonitored individual configured to take a first alcohol concentrationreading at a first time and a second alcohol concentration reading as asecond time using a sensor and under direction of a controller; and acomputing device operable to receive at least a subset of the pluralityof alcohol concentration readings and to calculate a baseline valueusing at least the first alcohol concentration reading and the secondalcohol concentration reading.
 23. The system of claim 22, wherein thesensor is a transdermal alcohol sensor.